// 代码索引 3-7-7-1
// Combining broadcasting with other operations
#include <iostream>
#include <Eigen/Dense>

int main()
{
    Eigen::MatrixXf m(2, 4);
    Eigen::VectorXf v(2);

    m << 1, 23, 6, 9,
        3, 11, 7, 2;

    v << 2,
        3;

    Eigen::Index index;
    // find nearest neighbour
    (m.colwise() - v).colwise().squaredNorm().minCoeff(&index);

    std::cout << "Nearest neighbour is column " << index << ":" << std::endl;
    std::cout << m.col(index) << std::endl;
}